The ice box is a free standing cabinet in the forward salon. It thru-bolts to the half-height “bulkhead” that is part of the grid that holds water and diesel tanks underneath the floor.
The whole unit will not fit through the companionway, requiring assembly inside the boat.
The cabinet carcass has supporting “ribs” to give structure. A mylar radiant resistant film lines the inside of the perimeter mahogany plywood that is the outside of the cabinet. The inside liner is a thin smooth white fiberglass plastic liner (manufactured by Crane Composites) laminate over half inch Coosa Board. Methacrylate structural adhesive glues the box joints and a generous fillet of Sikaflex seals the corners.
After assembly inside the boat, two-part polyurethane “dump foam” in the wall cavities gives insulation. Excepting vacuum panels, dump foam provides the best R value (slightly better R value than typical pink or blue polystyrene panels).
A PVC drain tube provides a drain to the bilge.
The cabinet will ultimately have a hard solid surface (Corian-like stuff).